Forms feed locking device

ABSTRACT

A locking or fastening device for use in the positioning of a forms feed drive along a transverse shaft of a business machine to accommodate different widths of record material, including a support plate fixed to the drive and slidable along the shaft and carrying a rockable lever, and a torsional spring surrounding the shaft and connected to the lever in such manner as to be selectively tightened on the shaft for locking the drive in position thereon and to be released from the shaft for unlocking the drive therefrom. The lever pivotally carries a link connected to one end of the spring, and the other end of the spring is connected to the lever pivot, the link pivot occupying an overcenter relationship with respect to the lever pivot in each of two different positions of the lever for retaining the spring in either a shaft-gripping or a shaft-nongripping condition.

United States Patent [72] Inventor Orville H. Shdllbarger Dayton, Ohio [21] Appl. No. 737,440 [22] Filed June 17, 1968 [4S] Patented June 8, 1971 [73] Assignee The National Cash Register Company Dayton, Ohio [54] FORMS FEED LOCKING DEVICE 16 Claims, 4 Drawing Figs.

[52] U.S. Cl 197/133, 226/19 [51] lnt.Cl B41j 15/16 [50] Field ofSearch 197/133; 24/157,123.5;226/19,15

[56] References Cited UNITED STATES PATENTS 1,659,111 2/1923 Lett 24 257 3,154,235 10/1964 Hubbard 197/133X 3,283,875 11/1966 Davies 197/133 Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Attorneys-Louis A. Kline, Wilbert Hawk, Jr. and George J.

Muckenthaler ABSTRACT: A locking or fastening device for use in the positioning of a forms feed drive along a transverse shaft of a business machine to accommodate different widths of record material, including a support plate fixed to the drive and slidable along the shaft and carrying a rockable lever, and a torsional spring surrounding the shaft and connected to the lever in such manner as to be selectively tightened on the shaft for locking the drive in position thereon and to be released from the shaft for unlocking the drive therefrom. The lever 'pivotally carries a link connected to one end of the spring, and the other end of the spring is connected to the lever pivot, the link pivot occupying an overcenter relationship with respect to the lever pivot in each of two different positions of the lever for retaining the spring in either a shaft-gripping or a shaftnongripping condition.

FORMS FEED LOCKING DEVICE BACKGROUND OF THE INVENTION In the field of locking and/or braking mechanisms for ad justably controlling the connection of driving or driven elements of a machine, the prior art shows generally the use of bands encircling and adapted to be frictionally engageable with one or the other of these elements, shows the use of braking segments which are automatically tightened about drums for preventing reverse motion of the drums upon stoppage of power .thereto, and shows spring-loaded retaining means which allow movement of parts when urged in one direction and which secure the parts when urged in the other direction. The prior art also specifically teaches the use of mechanism for laterally adjusting various machine elements along support members by means of levers having eccentric clamping surfaces engageable with support rods, as seen in U.S. Pat. No. 2,31 l ,051, issued Feb. 16, 1943, on the application of William H. Hope, .lr.; by means of a spring-urged wedge bar engageable with a crossbar to hold infeed guide plates in position, as seen in U.S. Pat. No. 3,159,263, issued Dec. 1, 1964, on the application of Peter E. Goreham; by a tapered gripper adaptable for locking and unlocking a member which is movable lineally or axially along a shaft, as shown in U.S. Pat. No. 3,172,297, issued Mar. 9, 1965, on the application of Carl G. Thiene; and by a spring-urged cam lever in clamping contact with a fixed shaft in one position of the lever, and detent means for holding the lever out of contact with the shaft as shown in U.S. Pat. No. 3,282,875, issued Nov. 8, 1966, on the application of Roy Dennis Davies.

While the above-mentioned patents show and describe various locking apparatus for use with precise elements or mechanisms capable of selective positioning in writing or printing machines, it should be noted that such apparatus provide either for spring-loaded means functioning in the locking condition or for a detented means operating in the unlocking condition in the positioning of such mechanisms. In this respect, generally the locked condition is considered the more important to maintain a tractor mechanism, or other type of forms feed drive, in its place so as to properly feed paper or like material through the machine during its operation. It should also be noted from the above patents that the locking or clamping apparatus includes an element, such as a lever or the like, which provides limited surface contact with a rod or a shaft to accomplish the desired locking function, the contact area being restricted by such element's form or shape, this restriction being disadvantageous especially when minutely adjusting the tractor mechanism for changeable conditions of the paper.

In the case of writing or printing machines which employ continuous roll or form paper, it is often necessary to adjust the width of the infeed drive mechanism to accommodate for different paper dimensions or for such changeable paper conditions. As is well known, the physical characteristics associated with changing temperature and humidity affect paper or like record material in such a manner that under certain environmental conditions the paper may contract and be held too tight, and under other conditions the paper may expand and become slack or wavy in its travel through a machine. These, of course, are undesirable conditions, as it is then difficult to obtain a clear and precise record on the paper if it is not properly maintained in its travel through the machine. The forms feed mechanism for a printer usually includes one or more of the tractor drives which have paper-engaging pins on belts or chains for advancing and controlling the rate of paper feed into the machine, the pins entering the apertures in the paper to drive it along. These tractor drives are generally supported on transverse rods or shafts, and, when it is desired to change the position of one or more of the drives to accommodate paper of a different width, or to correct for either a contracted or an expanded paper condition, the drive unit itthe amount of movement of the drive unit along the shaft may be minimal, as in the case of correcting for the condition of the paper, it is desirable that the drive be firmly secured when adjusted to a new operating position, so a positive type of locking means must be provided therefor. It is also desirable that the adjusting means for the tractor drive be retained in a drive-unit-locking position under optimum paper conditions during machine operation, and be retained in a drive-unit-unlocking position when the location of the drive along the shaft is changed to accommodate for these different paper conditions. Of course, wen adjusting for paper of a different width, the drive unit should be firmly maintained in the unlocked condition to allow for free movement thereof along the supporting shaft.

SUMMARY OF THE INVENTION The present invention relates to locking or fastening means for positively securing a drive mechanism along its supporting rods or shafts and, more particularly, related to a manually operated device for positively locking and unlocking a paper feed drive on a high-speed printer when the drive is positioned laterally along the supporting shafts. The invention includes a torsional member surrounding a shaft and lockable thereon to secure the drive in place and releasable therefrom to accommodate changing the location of the drive, and a plate or like member supported from the paper feed drive, the plate having pivoted thereon a handle or lever for operatively constricting and distending the torsion member. In the preferred embodiment, such torsion member is a spring, one end of which is pivotally connected to the lever and the other end of which is pivotally connected to a link in turn pivoted to thelever.

The pivot points for the lever and the link are so arranged and constructed that, when the lever is moved to the paper feed drive locked position (in a direction toward the shaft), the torsional spring is drawn tightly around the supporting shaft and the pivot points assume an overcenter relationship, thus insuring a positive grip on the shaft to secure the drive mechanism in place. When the lever is moved in the opposite direction (away from the shaft), the tension is released from the spring, thus withdrawing the grip on the shaft, and the pivot points again assume a relationship such that they are overcentered in the opposite direction to retain the spring in its released condition, whereby the drive mechanism can be freely and slidably moved along the shaft to the desired location. Adjusting of the drive mechanism along the shaft is therefrom accomplished by moving the lever from a positive locking condition to a positive unlocking condition, sliding the paper feed drive mechanism to the new location, and then moving the lever back to the locking condition.

In view of the above discussion, the principal object of the present invention is to provide a positive locking device for maintaining a paper feed drive mechanism in locked or set position along its supporting shaft.

Another object of the invention is to provide means for maintaining the locking device in an unlocking condition when such drive mechanism is repositioned along its shaft.

A further object of the invention is to provide such a locking device which is quickly and easily operated from the paper feed drive mechanism locking condition to the unlocking condition and which includes positive retention in either condition.

Additional advantages and features of the present invention will become clear and fully understood from a reading of the following description taken together with the annexed drawings, in which:

FIG. 1 is a view in side elevation of a paper feed tractor mechanism incorporating the locking device of the present invention;

FIG. 2 is a view, partly in section, taken on the line 2-2 of FIG. 1;

FIG. 3 is a view in side elevation of the locking device, portions being broken away, and showing the parts in the tractor mechanism locked condition; and

FIG. 4 is a similar view, showing the parts in the tractor mechanism unlocked condition.

Referring to FIG. 1, there is shown a side view of a tractor mechanism, generally designated as 10, carried on shafts 12 and 14, the shaft 12 being a splined shaft for driving the mechanism drive sprocket 13, and the shaft 14 being an idler or support shaft for the idler sprocket 15. The sprockets 13, 15 (only a portion of them being shown) are carried on the shafts 12 and 14 in freely slideable manner, and an endless belt or chain 16 is trained around the sprockets l3 and 15, the belt 16 having pin-type links 18 for engaging and driving continuous form paper 20, seen in FIG. 2, to feed such paper 20 past a printing station (not shown). Although the locking device of the present invention may be applicable for other mechanisms which demand adjustment along shafts or rods, the invention will be shown and described as a means for providing positive locking and unlocking of a forms feed tractor mechanism. In a printer, for instance, the paper is carried and driven by spaced tractors, the spacing depending upon the width of the paper, and the tractors being supported on crossshafts and adaptable to be slidably moved along the shafts. Either or both of the tractors may be repositioned along the shafts to accommodate paper of different widths. Likewise, either one or both of the tractors may be repositioned along the shafts to accommodate any change in paper size or shape due to temperature and humidity conditions.

The tractor mechanism is shown and described in detail in a pending application for US. Letters Patent, Ser. No. 726,396, filed May 3, 1968, in the names of Harold E. Hepp and Roger W. Biser, now US Pat. No. 3,507,431, issued Apr. 21, 1970. As illustrated, herein, it includes generally a body member 22 (FIG. 2), the shafts 12 and 14 journaled in such member 22, and the sprockets 13 and with the endless belt 16 and the links 18 thereon for driving the paper 20. A hinge plate 24 is secured to the body member 22, and a cover plate 26 is hingedly connected to the plate 24 to keep the paper in contact with a guide plate 30 as it travels along the tractor mechanism 10. Secured, as by copper brazing, to the hinge plate 24 are studs 31 and 32 having threaded bores for receiving screws 38 and 39 which are used to secure the locking device to the tractor mechanism hinge plate 24.

The locking device is contained or enclosed by a pair of plates 33 and 34, the plate 33 being disposed adjacent the studs 31 and 32 and having an upper, formed-over spacer or cover portion 35, which is the short side of the angle-shaped plate 33. The plate 34 is a flat plate corresponding in shape to the long side of the plate 33. Each of the plates 33 and 34-includes an aperture 27 for receiving the shaft 14, and the plate 34 additionally has a hub 29 fixed thereto for suitably carrying such shaft 14. Spacers or bushings 37 are placed between the plates 33, 34, and screws 38 and 39 are inserted through such bushings and threaded into the respective studs 31 and 32 to secure the locking device to the tractor mechanism hinge plate 24. FIG. 2 shows the relationship of the various parts arranged axially along the shaft 14.

A lever 45, located adjacent the plate 34, is pivotally supported on a stud 46 extending between the plates 33 and 34 (FIG. 2), said lever 45 extending upwardly and freely through a slot 67 in the cover portion 35 of the plate 33. As shown in FIGS. 3 and 4, the lever 45 includes a lower foot portion 49 and an upper handle portion 51, the foot portion 49 having a pair of apertures 47 and 48 therethrough for the lever pivot stud 46 and for a soon-to-be-described linkage connection 64. The handle portion 51 is of channel-shaped construction and includes on either side the notations locked and unlock" to readily indicate to the operator the condition of the device. The lever pivot stud 46 lies parallel to the shaft 14, so it is seen that the lever 45 can be rocked toward or away from the shaft 14.

Referring to FIGS. 3 and 4, a torsion spring 60, of one and one-half coils, is close wound on the shaft 14 such spring 60 having preformed hooked ends 61 and 62, to hook around the pivot stud 46 and around a stud 63 on a link 64, respectively.

The link 64 is pivotally connected to the lever foot portion 49 by means of a pin 65 in the above-noted aperture thereof.

As seen in FIG. 3, where the lever 45 is rocked toward the shaft 14, the extent of the rocking is limited by engagement of the lever 45 with one end surface 66 of a slot 67 in the cover portion 35 of the plate 33. A similar end surface 68 is contacted by the lever 45 when the lever is rocked away from the shaft, as seen in FIG. 4. In the locked condition, wherein the lever 45 is rocked toward the shaft 14 (FIG. 3), such action causes movement of the link 64 away from the shaft 14 and counterclockwise about the lever pivot stud 46. Since the spring end 61 is fixed on the stud 46 relative to the shaft 14, such movement of the link 64 draws the spring end 62 counterclockwise around the shaft 14, and the spring 60 is thus tightened around the shaft 14. In this locked condition, the pin 65 assumes an overcenter relationship with the pivot stud 46 in respect to the linkage stud 63, so that the lever 45 is positively retained in such locked position.

FIG. 4 shows the unlocked condition, wherein the lever 45 is rocked away from the shaft 14, the link 64 having moved toward the shaft 14 and clockwise around the pivot stud 46. The end 61 of the spring 60 is retained in position on the stud 46 relative to the shaft 14, but the spring end 62 has moved toward and clockwise around the shaft 14, which movement releases or unwinds the spring 60 from the shaft 14. The ends 61 and 62 are, of course, sufficiently free so that the studs 46 and 63 do not cause a binding effect, as the lever handle 51 is moved toward or away from the shaft 14. In the unlocked condition, the tractor mechanism 10 is free to be moved along the shaft 14 to a new position. The lever 45 is likewise retained in the unlocked position by reason of the pin 65 being overcenter with respect to the pivot stud 46 and the stud 63, and also because of the latent tension in the spring 60, which tends to unwind it to a shaft-nongripping or free position.

In the operation of the locking device, assume that the handle portion 51 is in its locked position (FIG. 3), whereby the spring 60 is drawn tightly about the shaft 14, thus fixing or holding the tractor mechanism 10 in position on the shafts 12 and 14. If it is then desired to reposition the tractor l0 axially along the shafts 12 and 14 (the desired transverse movement being slight to regain proper tension in the paper 20 or being greater to accommodate a paper of different width), the lever handle portion 51 is first swung to the unlocked position (FIG. 4), which releases the spring 60 from its tightened condition about the shaft 14, and the tractor mechanism 10 is thereafter manually moved along the shafts l2 and 14 to the new position. The lever handle 51 is automatically retained in this unlocked position by reason of the overcenter relationship of the pin 65 with the pivot studs 46 and 63, thus affording smooth action in repositioning the tractor. The handle portion 51 is of course then swingably returned to the locked position, thereby again drawing the spring 60 tight about the shaft 14 and locking the tractor mechanism 10 in the desired new position.

It is thus seen that herein shown and described is a locking device for use in the adjustment of a shaft-carried tractor mechanism 10 to accommodate different widths and conditions of paper 20 in a high-speed printing operation. While only one embodiment has been disclosed, variations on the present invention may occur to those skilled in the art, and it is to be understood that all such variations are contemplated as being within the scope of the invention. The invention is thus not to be taken as limited to the specific embodiment shown and described, nor, in fact, in any manner except as defined in the following claims.

What 1 claim is:

1. A locking device for securing a drive means along a transverse shaft of a business machine, the drive means having a body member, and said locking device including support means connected to and movable with the body member,

lever means pivotally connected to said support means and movable in a direction toward the shaft,

resilient means freely surrounding said shaft and pivotally connected at one end thereof to the lever means, and

linkage means pivotally connected to the lever means and connected to the other end of the resilient means whereby movement of the lever means in said direction displaces the linkage means to draw the resilient means tightly about the shaft.

2. A device in accordance with claim 1 wherein said resilient means is a torsional spring wrapped about the shaft.

3. A device in accordance with claim 1 wherein the linkage means includes a portion which assumes an overcenter relationship with respect to the lever means to retain the lever means in said direction.

4. Means for adjustment of a forms feed drive laterally along a main shaft ofa business machine, including support means adjacent and connected to said forms feed drive in position relative to the shaft for sliding therealong,

means pivotally connected with said support means and movable to and fro in a direction normal to said shaft, means surrounding said shaft arranged to be gripped thereabout and released therefrom, and having one end connected to said to-and-fro movable means, and

linkage means connected said to-and-fro movable means and the other end of the surrounding means for alternate gripping and releasing of the shaft by said surrounding means as the to-and-fro movable means is moved respectively toward and away from said shaft.

5. Means for adjustment in accordance with claim 4 wherein the surrounding means is a coiled torsional spring.

6. Means for adjustment in accordance with claim 4 wherein the means connecting the to-and-fro movable means and the other end of the surrounding means is a toggle member having end portions positioned in relation to the toand-fro movable means for maintaining the to-and-fro movable means in a direction toward said shaft for locking said drive and in a direction away from said shaft for unlocking said drive.

7. A locking device for securing a record material drive means along a transverse shaft of a business machine, the drive means having a body member, and said locking device including support means connected to and movable with the body member,

lever means pivotally connected to said support means and swingable toward and away from the shaft,

resilient means surrounding said shaft and pivotally connected at one end thereof to the lever means, and

linkage means pivotally connected to the lever means and connected to the other end of the resilient means whereby swinging movement of the lever means in one direction displaces the linkage means to draw the resilient means about the shaft for locking the drive means in one position thereon, and swinging movement of the lever 7 10. In a drive mechanism for feeding record material through a business machine having a main shaft thereacross, means for laterally adjusting said drive mechanism including a body member journaled on said shaft, said body member carrying the drive mechanism and slidable therewith along the shaft,

plate means connected to sad body member and spaced therefrom, a lever pivotally connected with said plate means, said lever being rockable toward and away from the main shaft, a torsional spring connected at one end thereof to the lever, said spring surrounding the main shaft and arranged to be tightened thereon and released therefrom, and a link pivotally connected with said lever and connected with the other end of said spring whereby rocking movement of the lever away from the main shaft swings the link for releasing the spring from the shaft to allow repositioning of the mechanism along the shaft, and rocking movement of the lever toward the main shaft swings the link for drawing the spring tightly around the shaft to secure the mechanism as repositioned therealong. 11. in a drive mechanism in accordance with claim 10 wherein the link includes a portion which assumes an overcenter relationship with respect to the lever to retain the spring either in the shaft-tightened condition or in the shaftreleased condition.

12. ln a drive mechanism in accordance with claim 10 including a pair of the body members spaced from each other whereby one or the other may be repositioned along the shaft to accommodate record material of different widths.

13. A locking device for use with different widths of form paper in a record-preparing machine having a driving shaft and a driven shaft, a tractor mechanism including a frame member, sprockets on the shafts, and belt means trained around the sprockets for feeding the paper, and said frame member, sprockets, and belt means being movable transversely as a unit along the shafts; said locking device including support plates carried on the driven shaft adjacent and secured to the frame member, a

lever pivotally connected to the support plates and swingable toward and away from the driven shaft, a

torsion spring coiled about the driven shaft and having one end thereof connected to the lever, and a link pivotally connected to the lever and connected to the other end of the spring, the swinging of the lever away from the driven shaft moving said link toward the driven shaft to release the tension in the spring, thereby unlocking the tractor mechanism for movement along the shafts, and the swinging of the lever toward the driven shaft moving said link away from the driven shaft to restore tension in the spring, thereby locking the tractor mechanism on the driven shaft.

14. A locking device in accordance with claim 13 wherein the link is a toggle member which assumes an overcenter relationship with respect to the lever to retain the lever either in the tractor mechanism locked or the unlocked condition.

15. A locking device in accordance with claim 13 wherein said lever includes means for indicating either the locked or the unlocked condition of the tractor mechanism.

16. A locking device in accordance with claim 13 wherein one of the support plates includes a cover portion having a slot therein for directing swinging movement of the lever. 

1. A locking device for securing a drive means along a transverse shaft of a business machine, the drive means having a body member, and said locking device including support means connected to and movable with the body member, lever means pivotally connected to said support means and movable in a direction toward the shaft, resilient means freely surrounding said shaft and pivotally connected at one end thereof to the lever means, and linkage means pivotally connected to the lever means and connected to the other end of the resilient means whereby movement of the lever means in said direction displaces the linkage means to draw the resilient means tightly about the shaft.
 2. A device in accordance with claim 1 wherein said resilient means is a torsional spring wrapped about the shaft.
 3. A device in accordance with claim 1 wherein the linkage means includes a portion which assumes an overcenter relationship with respect to the lever means to retain the lever means in said direction.
 4. Means for adjustment of a forms feed drive laterally along a main shaft of a business machine, including support means adjacent and connected to said forms feed drive in position relative to the shaft for sliding therealong, means pivotally connected with said support means and movable to and fro in a direction normal to said shaft, means surrounding said shaft arranged to be gripped thereabout and released therefrom, and having one end connected to said to-and-fro movable means, and linkage means connected said to-and-fro movable means and the other end of the surrounding means for alternate gripping and releasing of the shaft by said surrounding means as the to-and-fro movable means is moved respectively toward and away from said shaft.
 5. Means for adjustment in accordance with claim 4 wherein the surrounding means is a coiled torsional spring.
 6. Means for adjustment in accordance with claim 4 wherein the means connecting the to-and-fro movable mEans and the other end of the surrounding means is a toggle member having end portions positioned in relation to the to-and-fro movable means for maintaining the to-and-fro movable means in a direction toward said shaft for locking said drive and in a direction away from said shaft for unlocking said drive.
 7. A locking device for securing a record material drive means along a transverse shaft of a business machine, the drive means having a body member, and said locking device including support means connected to and movable with the body member, lever means pivotally connected to said support means and swingable toward and away from the shaft, resilient means surrounding said shaft and pivotally connected at one end thereof to the lever means, and linkage means pivotally connected to the lever means and connected to the other end of the resilient means whereby swinging movement of the lever means in one direction displaces the linkage means to draw the resilient means about the shaft for locking the drive means in one position thereon, and swinging movement of the lever means in the other direction displaces the linkage means to release the resilient means from about the shaft for allowing transverse movement of the drive means therealong.
 8. A device in accordance with claim 7 wherein said resilient means is a torsional spring wrapped about the shaft.
 9. A device in accordance with claim 7 wherein the linkage means includes a portion which assumes an overcenter relationship with respect to the lever means to retain the lever means in one or the other direction of its swinging movement.
 10. In a drive mechanism for feeding record material through a business machine having a main shaft thereacross, means for laterally adjusting said drive mechanism including a body member journaled on said shaft, said body member carrying the drive mechanism and slidable therewith along the shaft, plate means connected to sad body member and spaced therefrom, a lever pivotally connected with said plate means, said lever being rockable toward and away from the main shaft, a torsional spring connected at one end thereof to the lever, said spring surrounding the main shaft and arranged to be tightened thereon and released therefrom, and a link pivotally connected with said lever and connected with the other end of said spring whereby rocking movement of the lever away from the main shaft swings the link for releasing the spring from the shaft to allow repositioning of the mechanism along the shaft, and rocking movement of the lever toward the main shaft swings the link for drawing the spring tightly around the shaft to secure the mechanism as repositioned therealong.
 11. In a drive mechanism in accordance with claim 10 wherein the link includes a portion which assumes an overcenter relationship with respect to the lever to retain the spring either in the shaft-tightened condition or in the shaft-released condition.
 12. In a drive mechanism in accordance with claim 10 including a pair of the body members spaced from each other whereby one or the other may be repositioned along the shaft to accommodate record material of different widths.
 13. A locking device for use with different widths of form paper in a record-preparing machine having a driving shaft and a driven shaft, a tractor mechanism including a frame member, sprockets on the shafts, and belt means trained around the sprockets for feeding the paper, and said frame member, sprockets, and belt means being movable transversely as a unit along the shafts; said locking device including support plates carried on the driven shaft adjacent and secured to the frame member, a lever pivotally connected to the support plates and swingable toward and away from the driven shaft, a torsion spring coiled about the driven shaft and having one end thereof connected to the lever, and a link pivotally connected to the lever and connected to the other end of The spring, the swinging of the lever away from the driven shaft moving said link toward the driven shaft to release the tension in the spring, thereby unlocking the tractor mechanism for movement along the shafts, and the swinging of the lever toward the driven shaft moving said link away from the driven shaft to restore tension in the spring, thereby locking the tractor mechanism on the driven shaft.
 14. A locking device in accordance with claim 13 wherein the link is a toggle member which assumes an overcenter relationship with respect to the lever to retain the lever either in the tractor mechanism locked or the unlocked condition.
 15. A locking device in accordance with claim 13 wherein said lever includes means for indicating either the locked or the unlocked condition of the tractor mechanism.
 16. A locking device in accordance with claim 13 wherein one of the support plates includes a cover portion having a slot therein for directing swinging movement of the lever. 